Interventional management of acute coronary syndromes

Percutaneous coronary intervention is an effective treatment for a range of coronary syndromes. Although the success rate of the interventions has increased in recent years to more than 90%, percutaneous coronary procedures are still associated with short-term and long-term complications. The most common angiographic short-term complication of balloon angioplasty is acute vessel closure. Clinically, periprocedural non-e wave myocardial infarctions are common during or immediately following the percutaneous intervention. These complications are associated with adverse clinical prognosis. Formation of platelet-rich thrombi plays a major role in the pathophysiology of acute complications of balloon angioplasty. Potent platelet inhibition with glycoprotein IIb-IIIa inhibitors reduces the incidence of periprocedural death and myocardial infarctions, a benefit that persists at long-term follow-up. The long-term complication of percutaneous interventions is restenosis, which frequently requires repeated revascularization because of ischemic pain. Most pharmacological therapies have proved ineffective for the prevention of restenosis. This may not be surprising, as new evidence shows that the primary mechanism of restenosis may be arterial remodeling. Implantation of coronary stents prevents lumen narrowing due to the remodeling process, and coronary stenting significantly reduces the need for target vessel revascularization. Restenosis is not completely eliminated, however, and new treatment modalities aimed at prevention of in-stent stenosis are actively being sought.